Eric Coates (August 27, 1886 – December 21, 1957) was an English composer of light music and a viola player.

He was born in Hucknall in Nottinghamshire, the son of a doctor, and studied music at the Royal Academy of Music in London from 1906, receiving viola lessons from Lionel Tertis. From 1910 he played in the Queen's Hall Orchestra under Henry Wood, becoming principal violist in 1912. By the end of the 1910s he was concentrating entirely on composition, having been forced to give up the viola for medical reasons. He had an early success with the overture "The Merrymakers" (1922), but more popular was the London Suite (1933). The last movement of this, "Knightsbridge", was used by the BBC to introduce their radio programme "In Town Tonight".

Coates' music, with its simple and memorable melodies, proved particularly effective for theme music, and the BBC also used "Calling All Workers" (1940) as the theme for "Music While You Work"; "By the Sleepy Lagoon" (1930) is still used to introduce the long-running "Desert Island Discs". Coates is also well-known for his film score for The Dam Busters (1954); the title March is particularly famous. His songs, some with lyrics by Arthur Conan Doyle, are less well remembered.

Coates' autobiography, Suite in Four Movements, was published in 1953. He died in Chichester having suffered a stroke.

Eric Coates was no relation to Albert Coates, the contemporary conductor and composer.